260
S. G. Nedilko
Described below the MCC composites were prepared by “dry” cool-pressed
methods. Chemically pure microcrystalline cellulose tablets manufactured at
ANCYR-B (Ukraine) were used as starting material for preparation of the composite
samples under study. (Starting cellulose materials are marked below as SC.) First,
cellulose tablets were grinded and dispersed using high-speed rotation mill. Then,
some part of the resulting powder was mixed with a certain amount of the previously
made nanosized oxide powder. (The sample of un-doped micro-/nanocellulose is
marked as C0.) The mix of ∼ 0.5 g mass was dissolved in 50 ml of high purity
ethanol and undergone ultrasonic treatment (frequency, f = 4.2 kHz; time of the
treatment, t = 20 min.). After that, obtained suspense stood for 30 min, and obtained
precipitate was filtered via paper filter. Prepared powder was dried at ambient air
conditions and room temperature (RT) followed by compression at high pressure of
1.8*10 4 kPa/m 2 . The samples under experiments were of the discs form of ∼ 10 mm
average diameter. The thickness of the discs was ∼ 1 mm. The amount of oxide
was in the range 1–200 mg for different “dry” samples, while the mass of MCC
was 450 mg for each of those samples. Thus, below we denote the sample only as
mass and formulae of corresponding oxide, e.g., 10-K 2 Eu(PO 4 )(MoO 4 ) denotation
means that the sample contains 10 mg of K 2 Eu(PO 4 )(MoO 4 ) oxide incorporated
into 450 mg of MCC. Used oxides could be made by three various procedures:
solid-state reaction, coprecipitation, and sol–gel. We have found recently that
luminescence intensity for each oxide depends on the RE ion concentration and
on the way of their synthesis [71, 72]. In fact, we have found that for LaVO 4
doped with RE, the average size was 1–2 μm for solid-state way of the synthesis,
0.2–0.5 μm for the coprecipitation, and 0.1–0.2 μm for the sol–gel way. Moreover,
luminescence of these oxides made by sol–gel method was near three times higher
than for the oxides made by coprecipitation and about ten times higher than for the
samples made by solid-state synthesis [71]. So, the samples made by the sol–gel way
were selected for experiments with composites. In this way, that oxide procedure
and that RE concentration which showed higher PL intensity were selected for
composite preparation and further experiments.
As we have noted in the Sects. 15.1 and 15.1.1, the morphology, structure, and
other properties of the PMM/NC samples depend on their composition and on the
way of the sample preparation. Thus, various characteristics had to be studied,
as the samples were made for the first time. This required us to use a variety of
experimental methods. Those were scanning electron microscopy (SEM), chemical
element analysis, X-ray diffractometry (XRD), luminescence spectroscopy, and
dielectric characteristic measurements.
Characterization of the sample topology was performed by means of the scanning
electron microscopy (SEM). Scanning electron microscope JAMP-9500F Field
Emission Auger Microprobe (JEOL, USA) equipped with X-ray microanalyzer
INCA PentaFetx3 (Oxford instruments) was used for SEM measurements. Besides
the SEM imaging, microelement analysis of various areas of the samples was also
performed using the same microscope.
The X-ray diffraction patterns (XRD) were collected using a conventional
powder diffractometer DRON-3 M equipped with BSV-28 tube (λ rad = 1.54178 Å)
S. G. Nedilko
Described below the MCC composites were prepared by “dry” cool-pressed
methods. Chemically pure microcrystalline cellulose tablets manufactured at
ANCYR-B (Ukraine) were used as starting material for preparation of the composite
samples under study. (Starting cellulose materials are marked below as SC.) First,
cellulose tablets were grinded and dispersed using high-speed rotation mill. Then,
some part of the resulting powder was mixed with a certain amount of the previously
made nanosized oxide powder. (The sample of un-doped micro-/nanocellulose is
marked as C0.) The mix of ∼ 0.5 g mass was dissolved in 50 ml of high purity
ethanol and undergone ultrasonic treatment (frequency, f = 4.2 kHz; time of the
treatment, t = 20 min.). After that, obtained suspense stood for 30 min, and obtained
precipitate was filtered via paper filter. Prepared powder was dried at ambient air
conditions and room temperature (RT) followed by compression at high pressure of
1.8*10 4 kPa/m 2 . The samples under experiments were of the discs form of ∼ 10 mm
average diameter. The thickness of the discs was ∼ 1 mm. The amount of oxide
was in the range 1–200 mg for different “dry” samples, while the mass of MCC
was 450 mg for each of those samples. Thus, below we denote the sample only as
mass and formulae of corresponding oxide, e.g., 10-K 2 Eu(PO 4 )(MoO 4 ) denotation
means that the sample contains 10 mg of K 2 Eu(PO 4 )(MoO 4 ) oxide incorporated
into 450 mg of MCC. Used oxides could be made by three various procedures:
solid-state reaction, coprecipitation, and sol–gel. We have found recently that
luminescence intensity for each oxide depends on the RE ion concentration and
on the way of their synthesis [71, 72]. In fact, we have found that for LaVO 4
doped with RE, the average size was 1–2 μm for solid-state way of the synthesis,
0.2–0.5 μm for the coprecipitation, and 0.1–0.2 μm for the sol–gel way. Moreover,
luminescence of these oxides made by sol–gel method was near three times higher
than for the oxides made by coprecipitation and about ten times higher than for the
samples made by solid-state synthesis [71]. So, the samples made by the sol–gel way
were selected for experiments with composites. In this way, that oxide procedure
and that RE concentration which showed higher PL intensity were selected for
composite preparation and further experiments.
As we have noted in the Sects. 15.1 and 15.1.1, the morphology, structure, and
other properties of the PMM/NC samples depend on their composition and on the
way of the sample preparation. Thus, various characteristics had to be studied,
as the samples were made for the first time. This required us to use a variety of
experimental methods. Those were scanning electron microscopy (SEM), chemical
element analysis, X-ray diffractometry (XRD), luminescence spectroscopy, and
dielectric characteristic measurements.
Characterization of the sample topology was performed by means of the scanning
electron microscopy (SEM). Scanning electron microscope JAMP-9500F Field
Emission Auger Microprobe (JEOL, USA) equipped with X-ray microanalyzer
INCA PentaFetx3 (Oxford instruments) was used for SEM measurements. Besides
the SEM imaging, microelement analysis of various areas of the samples was also
performed using the same microscope.
The X-ray diffraction patterns (XRD) were collected using a conventional
powder diffractometer DRON-3 M equipped with BSV-28 tube (λ rad = 1.54178 Å)